Head checking means for power operated pressing machines



E. DAVIS Oct. 27, 1931.

HEAD CHECKING MEANS FOR POWER OPERATED PRESSING MACHINES Filed Dec. 12,1927 Patented Oct. 27, 1931 UNITED STATES PATENT OFFICE-- ERNEST DAVIS,OF SYRACUSE, NEW YORK, ASSIGNOR TO THE PROSPERITY COMPANY, INC., OFSYRACUSE, NEW YORK, A CORPORATION OF NEW YORK HEAD CHECKING MEANS FORPOWER OPERATED PRESSING- MACHINES Application filed December 12, 1927.Serial No. 239,389.

g This invention relates to machines having an opening and closingmovement as pressing machines, and has for its object a particularlysimple and efiicient mechanism for retarding the opening and closingmovement of the movable element or head, particularly the closingmovement as the movable element approaches closed position, andrelieving I the retarding action during the final portions ure 1.

Figure 3 is an enlarged longitudinal sec-. tional view of the retardingmeans.

This invention comprises, generally, means for checking the movement ofthe movable element or press head of the pressing machine toward theother element or buck as the head approaches closed position, andrelieving the checking action during the final portion of the closingmovement. The checking means is constructed also to check to some extentthe opening movement during an intermediate portion only thereof, andrelieve the movable element of the checking action as the movablepressing element or head approaches its wide open position. 1

In power press machines, the power first applied much be sufiicient toovercome the inertia of the press head but once the press head is inmotion, it comes down against the stationary pressing element or buckwith a jarring or slamming action. Likewise in opening the press, thepress head gains momentum on its upward movement and comes to a stopwith a more or less violent or jarring action.

By my invention, both the opening and closing movements are checkedduring the intermediate parts only of such movements, and the movableelement is relieved of the checking action at the end of its closingmovement when final pressure is being applied and also to a less extentat the end of its opening movement. The checking of the opening movementis not of as much consequence as the checking of the closing movement.

The pressing machine may be of any suitable form, size or construction,that here shown including a head 1 movable toward and from a buck 2mounted on a suitable bench 3 carried by a suitable frame. The actuatingmechanism for the head comprises a motor as a cylinder 4 having a pistontherein, the rod 5 of which is connected'to the head 1 through suitablemotion transmitting connections. These connections are here shown asincluding a horizontal lever 6 pivoted at 7 to the frame and having anupwardly extending arm 8 connected to a link 9 which is pivoted at 10 tothe rear arm of a lever 11 pivoted between its ends at 12 to the frame.The lever 11 carries the head 1 at its front end. The parts 8 and 9constitute a toggle. The lever 11 is provided with a suitablecounterweight 13 and springs 14 and 15 to open the press, as thecylinder 4: is single acting. However, the cylinder with the pistontherein is the prime mover. The control of air or other motor fluid toand from the cylinder is effected by any suitable manually operablemeans. The manual means here shown includes a push button 16 whichoperates to open an intake valve in casing 16, and a lever 17 whichopens an exhaust valve in said casfhe construction of the parts thus fardescribed forms no part of this invention.

The checking means forming the subject matter of this invention acts tocheck the closing movement of the press as the head 1 approaches thebuck 2 and relieves the head of the checking action when the finalpressure is being applied by the air pressure in the cylinder 4 againstthe piston, and also acts to slightly check the opening movement of thepress under the influence of counterweight 13 andsprings 14 and 15,before the head comes to wide open position. The checking means is hereshown as a cylinder 18 and a piston 19 in the cylinder, one of theseparts, usually the piston, being movable and fits said intermediateportion. The end portions are usually of truncated conical form andtaper toward the cylindrical intermediate portion 20. In order that themachine may open quickly, the checking efiect is lessened by providing aby-pass for the fluid from one side of the piston to the other. As hereillustrated, the by-pass is provided in the piston, and the piston isshown as formed with passages 23 therethrough which are closed duringthe down st oke of the piston by a flat valve 24. During the up orreturn stroke of the piston the flat valve is pressed away from thepassages 23 by the fluid. The fiat valve 24 is, in effect, a checkvalve.

A piston rod 25 slides in a head 26 of the cylinder 18 and is connectedto one of the motion transmitting parts here shown as the toggle link 8.The connection between the toggle link 8 and the piston rod 25 comprisesa lever 27 pivoted between its ends to the frame at 28, one arm of thelever being connected to the swinging toggle link 8 by a link 29 and theother arm being connected to the piston rod by a swinging link 30pivoted at 31 to the lever 27 and at 32 to a head 33 on the end of thepiston rod.

The cylinder is usually fixed to a suitable part of the frame as therear leg 34 and is located below the table or bench 3. The piston rodextends through the upper end of the cylinder, and hence the connectingrod'30 extends along one side of the cylinder beyond the lower endthereof where it is pivoted at 31 to the lever 27.

In operation, when motor fluid is permitted to pass into the upper endof the cylinder 4, the piston 19 is in the upper portion 22 of thecylinder 18 and there is practically no checking effect until the head 1has moved far enough toward the buck 2 to carry the piston 19 in thecontractedportion 20 of the cylinder when the closing movement of thehead 1 is retarded momentarily until the momentum of the head isovercome or nearly overcome.

The piston 19 then moves into the larger lower end portion 21of thecylinder thus relieving the retarding or checking effect while flillllunchecked final pressure is being ap- 'ed.' p The press is held closedby the air in the cylinder 4 and when this air is released, by operatingthe lever 7, the head opens under the influence of the counterweight 13and springs 14 and 15. During the beginning of such opening movement,there is no checking effect while the weight 13 and springs 14 and 15are overcoming the inertia of the head. Thereafter when the press partlyopen, the

piston 19 again reaches the contracted portion 20 of the cylinder andthe momentum of the head during its upwardmovement is momentarilychecked to a slight extent, the checking effect being decreased becausethe fluid is now free to pass through the passages 23.

WVhat I claim is:

1. In a pressing machine, upper and lower pressing elements, the upperelement being movable towardand from the lower element, actuatingmechanism for moving the upper element toward and from the lower, andmeans for checking the operation of the upper element after it has beenstarted in motion, and relieving it of the-checking force as the upperelement comes into coaction with the lower element and when itapproaches the limit of its upward movement away from the lower element.

2. A pressing machine including co-operating pressing elements, one ofwhich is movable toward and from the other, actuating mechanism foractuating the movable element, and means for retarding the movable.element during intermediate parts only of the opening and closingmovements thereof.

3. A pressing machine comprising coopcrating pressing elements, one ofwhich is movable toward and from the other, mechanism for actuating thevmovable element, means for retarding the movable element duringintermediate parts of the opening and closing movements thereof, saidretarding means including mechanism for causing a greater retardingeffect when the movable element moves in one direction than when saidmovable element moves in the other direction.

4. In a pressing machine, the combination of a fixed pressing element, amovable pressing element, actuating mechanism for said movable element,means cooperating with said actuating mechanism to retard the motion ofsaid movable element during a part of its movement in each direction.

5. In a pressing machine, the combination of a fixed pressing element, amovable pressing element, actuating mechanism for said movable element,means cooperating with said actuating mechanism to retard the inotion ofsaid movable element during a. part of its movement ineach direction,and dis- 'aaaaeea tion, and discontinue the retarding efiect as themovable element approaches its limit of travel ineach direction, andvalve mechanism in said fiuid retarding means operable g to decreaseretarding action as the movable element is moved in one direction.

In testimony whereof, I have hereunto signed my name, at Syracuse, inthe county of .Onondaga, and in the" State of New York, 10 this 8th dayof Dec, 1927.

ERNEST DAVIS.

